A 25-year-old woman with MEN2B syndrome is found to have a germline RET mutation at codon 918 (M918T). What is the recommended timing for prophylactic thyroidectomy?

• A When calcitonin becomes elevated
• B At age 5 years
• C At age 10 years
• D Within the first year of life ✓

Explanation

MEN2B with codon 918 mutation carries the highest risk of aggressive medullary thyroid carcinoma, with metastases reported in infancy. Prophylactic thyroidectomy is recommended within the first year of life, ideally within the first 6 months. MEN2D codon 634 mutations warrant surgery by age 5 years.

Reference: Williams Textbook of Endocrinology, 14th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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